The word assassin is often believed to derive from the word Hashshashin (Arabic: حشّاشين, ħashshāshīyīn, also Hashishin, Hashashiyyin, or Assassins),[2] and shares its etymological roots with hashish (/hæˈʃiːʃ/ or /ˈhæʃiːʃ/; from Arabic: حشيشḥashīsh).[3] It referred to a group of NizariShia Muslims who worked against various political targets.

Founded by Hassan-i Sabbah, the Assassins were active in the fortress of Alamut in Persia from the 8th to the 14th centuries, and later expanded by capturing forts in Syria. The group killed members of the Abbasid, Seljuq, Fatimid, and Christian Crusader elite for political and religious reasons.[4]

Although it is commonly believed that Assassins were under the influence of hashish during their killings or during their indoctrination, there is debate as to whether these claims have merit, with many Eastern writers and an increasing number of Western academics coming to believe that drug-taking was not the key feature behind the name.[5]

The earliest known use of the verb "to assassinate" in printed English was by Matthew Sutcliffe in A Briefe Replie to a Certaine Odious and Slanderous Libel, Lately Published by a Seditious Jesuite, a pamphlet printed in 1600, five years before it was used in Macbeth by William Shakespeare (1605).[6][7]

In the Middle Ages, regicide was rare in Western Europe, but it was a recurring theme in the Eastern Roman Empire. Blinding and strangling in the bathtub were the most commonly used procedures. With the Renaissance, tyrannicide—or assassination for personal or political reasons—became more common again in Western Europe. High medieval sources mention the assassination of King Demetrius Zvonimir (1089), dying at the hands of his own people, who objected to a proposition by the Pope to go on a campaign to aid the Byzantines against the Seljuk Turks. This account is, however, contentious among historians, it being most commonly asserted that he died of natural causes. The myth of the "Curse of King Zvonimir" is based on the legend of his assassination.[15] In 1192, Conrad of Montferrat, the de factoKing of Jerusalem, was killed by an assassin.

In Japan, a group of assassins called the Four Hitokiri of the Bakumatsu killed a number of people, including Ii Naosuke who was the head of administration for the Tokugawa shogunate, during the Boshin War.[17] Most of the assassinations in Japan were committed with bladed weaponry, a trait that was carried on into modern history. A video-record exists of the assassination of Inejiro Asanuma, using a sword.[18]

Liaquat Ali Khan, the first Prime Minister of Pakistan, was assassinated by Saad Akbar, a lone assassin, in 1951. Conspiracy theorists believe his conflict with certain members of the Pakistani military (Rawalpindi conspiracy) or suppression of Communists and antagonism towards the Soviet Union, were potential reasons for his assassination.

The U.S. Senate Select Committee chaired by Senator Frank Church (the Church Committee) reported in 1975 that it had found "concrete evidence of at least eight plots involving the CIA to assassinate Fidel Castro from 1960 to 1965."[21]

Most major powers repudiated Cold War assassination tactics, though many allege that this was merely a smokescreen for political benefit and that covert and illegal training of assassins continues today, with Russia, Israel, the U.S., Argentina, Paraguay, Chile, and other nations accused of engaging in such operations.[22] In 1986, U.S. President Ronald Reagan (who survived an assassination attempt himself) ordered the Operation El Dorado Canyon air raid on Libya in which one of the primary targets was the home residence of Libyan ruler Muammar Gaddafi. Gaddafi escaped unharmed; however, his adopted daughter Hanna was claimed to be one of the civilian casualties.

After the Iranian Revolution of 1979, the new Islamic government of Iran began an international campaign of assassination that lasted into the 1990s. At least 162 killings in 19 countries have been linked to the senior leadership of the Islamic Republic of Iran.[23] This campaign came to an end after the Mykonos restaurant assassinations, because a German court publicly implicated senior members of the government and issued arrest warrants for Ali Fallahian, the head of the Iranian Intelligence.[24] Evidence indicates that Fallahian's personal involvement and individual responsibility for the murders were far more pervasive than his current indictment record represents.[25]

Anwar Sadat, President of the Arab Republic of Egypt (formerly President of the United Arab Republic), was assassinated October 6, 1981, during the annual parade celebrating Operation Badr, the opening maneuver of the Yom Kippur War.

Swedish prime minister Olof Palme was murdered by a gun-wielding man close to midnight on February 28, 1986, after having visited a cinema with his wife. The couple were not accompanied by a body guard detail. The identity of the assassin and the reason for the murder are still unknown.

On August 17, 1988, President of Pakistan Gen. M. Zia ul Haqdied alongside 31 others including the Chief of Staff of the Pakistani Armed Forces, the US Ambassador to Pakistan and the chief of the US Military Mission to Pakistan when his C-130 transport plane mysteriously crashed. The crash is widely considered – in Pakistan – to be an act of political assassination.[27]

In post-Saddam Iraq, the Shiite-dominated government used death squads to perform extrajudicial executions of radical Sunni Iraqis, with some alleging that the death squads were trained by the U.S.[28][29] Concrete allegations have since surfaced that the Iranian government has actively armed and funded Shia death-squads in post-Saddam Iraq.[30]

In Lebanon, the assassination of former Prime Minister Rafik Hariri on February 14, 2005, prompted an investigation by the United Nations. The suggestion in the resulting Mehlis report that there was Syrian involvement, prompted the Cedar Revolution, which drove Syrian troops out of Lebanon.

In Guinea Bissau, President João Bernardo Vieira was assassinated in the early hours of March 2, 2009, in the capital, Bissau. Unlike typical assassinations his death was not swift; he first survived an explosion at the Presidential Villa, was then shot and wounded, and finally was butchered with machetes. His assassination was carried out by renegade soldiers who were apparently revenging the killing of General Tagme Na Waie, the Chief of Staff of the Armed Forces of Guinea Bissau, who had been killed in a bomb explosion the day before.

Assassination for military purposes has long been espoused – Sun Tzu, writing around 500 BC, argued in favor of using assassination in his book The Art of War. Nearly 2000 years later, in his book The Prince, Machiavelli also advises rulers to assassinate enemies whenever possible so they won't pose a threat.[32] An army and even a nation might be based upon and around a particularly strong, canny, or charismatic leader, whose loss could paralyze the ability of both to make war.

For similar and additional reasons, assassination has also sometimes been used in the conduct of foreign policy. The costs and benefits of such actions are difficult to compute, especially when they depend upon the policies of a successor, and one study has found that perceptual biases held by leaders often negatively affect decision making in this area, such that decisions made to go forward with assassinations often reflect the vague hope that any successor might be better.[33]

In both military and foreign policy assassinations, there is the risk that the target could be replaced by an even more competent leader, or that such a killing (or a failed attempt) will "martyr" a leader and lead to greater support of his or her cause (by showing the moral ruthlessness of the assassins). Faced with particularly brilliant leaders, this possibility has in various instances been risked, such as in the attempts to kill the Athenian Alcibiades during the Peloponnesian War. A number of additional examples from World War II show how assassination was used as a tool:

During the Vietnam War, partly in response to Viet Cong assassinations of government leaders, the U.S. engaged in the Phoenix Program to assassinate Viet Cong leaders and sympathizers, and killed between 6,000 and 41,000 people, with official 'targets' of 1,800 per month.[citation needed]

Insurgent groups have often employed assassination as a tool to further their causes. Assassinations provide several functions for such groups, namely the removal of specific enemies and as propaganda tools to focus the attention of media and politics on their cause.

Basque terrorists ETA in Spain have assassinated many security and political figures since the late 1960s, notably the President of the Government of Spain Luis Carrero Blanco, 1st Duke of Carrero-Blanco Grandee of Spain, in 1973. Since the early 1990s, they have also targeted academics, journalists and local politicians who publicly disagreed with them.

The Red Brigades in Italy carried out assassinations of political figures, as to a lesser extent, did the Red Army Faction in Germany in the 1970s and 1980s.

In the Vietnam War, Communist insurgents routinely assassinated government officials and individual civilians deemed to offend or rival the revolutionary movement. Such attacks, along with widespread military activity by insurgent bands, almost brought the Diem regime to collapse before the U.S. intervention.[35]

A major study about assassination attempts in the U.S. in the second half of the 20th century came to the conclusion that most prospective assassins spend copious amounts of time planning and preparing for their attempts. Assassinations are thus rarely a case of 'impulsive' action.[36]

However, about 25% of the actual attackers were found to be delusional, a figure that rose to 60% with 'near-lethal approachers' (people apprehended before reaching their target). This shows that while mental instability plays a role in many modern-age assassinations, the more delusional attackers are less likely to succeed in their attempt. The report also found that around two-thirds of attackers had previously been arrested (not necessarily for related offenses), that 44% had a history of serious depression, and that 39% had a history of substance abuse.[36]

With the advent of effective ranged weaponry, and later firearms, the position of an assassination target was more precarious. Bodyguards were no longer enough to hold back determined killers, who no longer needed to directly engage or even subvert the guard to kill the leader in question. Moreover, the engagement of targets at greater distance dramatically increased the chances of an assassin's survival. The first heads of government to be assassinated with a firearm were the Regent Moray of Scotland in 1570, and William the Silent, the Prince of Orange of the Netherlands in 1584. Gunpowder and other explosives also allowed the use of bombs or even greater concentrations of explosives for deeds requiring a larger touch.

Explosives, especially the car bomb, become far more common in modern history, with grenades and remote-triggered land mines also used, especially in the Middle East and Balkans (the initial attempt on Archduke Franz Ferdinand's life was with a grenade). With heavy weapons, the rocket-propelled grenade (RPG) has become a useful tool given the popularity of armored cars (discussed below), while Israeli forces have pioneered the use of aircraft-mounted missiles,[37] as well as the innovative use of explosive devices.

A sniper with a precision rifle is often used in fictional assassinations. However, certain pragmatic difficulties attend long-range shooting, including finding a hidden shooting position with a clear line-of-sight, detailed advance knowledge of the intended victim's travel plans, the ability to identify the target at long range, and the ability to score a first-round lethal hit at long range, usually measured in hundreds of meters. A dedicated sniper rifle is also expensive, often costing thousands of dollars because of the high level of precision machining and hand-finishing required to achieve extreme accuracy.[38]

Despite their comparative disadvantages, handguns are more easily concealable, and consequentially much more commonly used than rifles. Of 74 principal incidents evaluated in a major study about assassination attempts in the U.S. in the second half of the 20th century, 51% were undertaken by a handgun, 30% with a rifle or shotgun, 15% used knives, and 8% explosives (usage of multiple weapons/methods was reported in 16% of all cases).[36]

In the case of state-sponsored assassination, poisoning can be more easily denied. Georgi Markov, a Bulgarian dissident was assassinated by ricin poisoning. A tiny pellet containing the poison was injected into his leg through a specially designed umbrella. Widespread allegations involving the Bulgarian government and KGB have not led to any legal results. However, after the fall of the USSR, it was learned that the KGB had developed an umbrella that could inject ricin pellets into a victim, and two former KGB agents who defected said the agency assisted in the murder.[39] The CIA made several attempts to assassinate Fidel Castro, many of the schemes involving poisoning his cigars. In the late 1950s, KGB assassin Bohdan Stashynsky killed Ukrainian nationalist leaders Lev Rebet and Stepan Bandera with a spray gun that fired a jet of poison gas from a crushed cyanide ampule, making their deaths look like heart attacks.[40] A 2006 case in the UK concerned the assassination of Alexander Litvinenko who was given a lethal dose of radioactive polonium-210, possibly passed to him in aerosol form sprayed directly onto his food. Litvinenko, a former KGB agent, had been granted asylum in the UK in 2000 after citing persecution in Russia. Shortly before his death he issued a statement accusing President of RussiaVladimir Putin of involvement in his assassination. President Putin denies he had any part in Litvinenko's death.[41]

Targeted killing is the intentional killing–by a government or its agents–of a civilian or "unlawful combatant" who is not in the government's custody. The target is a person asserted to be taking part in an armed conflict or terrorism, whether by bearing arms or otherwise, who has thereby lost the immunity from being targeted that he would otherwise have under the Third Geneva Convention.[42] Note that this is a different term and concept from that of "targeted violence" as used by specialists who study violence.

On the other hand, Georgetown Law Professor Gary Solis, in his 2010 book entitled The Law of Armed Conflict: International Humanitarian Law in War,[43] writes: "Assassinations and targeted killings are very different acts".[42] The use of the term assassination is opposed, as it denotes murder, whereas the terrorists are targeted in self-defense, and thus it is viewed as a killing, but not a crime.[44] Judge Abraham Sofaer, former federal judge for the U.S. District Court for the Southern District of New York, wrote on the subject:

When people call a targeted killing an "assassination," they are attempting to preclude debate on the merits of the action. Assassination is widely defined as murder, and is for that reason prohibited in the United States ... U.S. officials may not kill people merely because their policies are seen as detrimental to our interests ... But killings in self-defense are no more "assassinations" in international affairs than they are murders when undertaken by our police forces against domestic killers. Targeted killings in self-defense have been authoritatively determined by the federal government to fall outside the assassination prohibition.[45]

Author and former U.S. Army Captain Matthew J. Morgan has argued that "there is a major difference between assassination and targeted killing ... targeted killing [is] not synonymous with assassination. Assassination ... constitutes an illegal killing."[46] Similarly, Amos Guiora, professor of law at the University of Utah, writes: "Targeted killing is ... not an assassination", Steve David, Professor of International Relations at Johns Hopkins University, writes: "There are strong reasons to believe that the Israeli policy of targeted killing is not the same as assassination". Syracuse Law Professor William Banks and GW Law Professor Peter Raven-Hansen write: "Targeted killing of terrorists is ... not unlawful and would not constitute assassination", Rory Miller writes: "Targeted killing ... is not 'assassination'". Associate Professor Eric Patterson and Teresa Casale write: "Perhaps most important is the legal distinction between targeted killing and assassination".[47][48][49][49][50]

On the other hand, the American Civil Liberties Union also states on its website, "A program of targeted killing far from any battlefield, without charge or trial, violates the constitutional guarantee of due process. It also violates international law, under which lethal force may be used outside armed conflict zones only as a last resort to prevent imminent threats, when non-lethal means are not available. Targeting people who are suspected of terrorism for execution, far from any war zone, turns the whole world into a battlefield."[51]
Yael Stein, the research director of B'Tselem, The Israeli Information Center for Human Rights in the Occupied Territories, also states in her article "By Any Name Illegal and Immoral: Response to 'Israel's Policy of Targeted Killing'"[52]

"The argument that this policy affords the public a sense of revenge and retribution could serve to justify acts both illegal and immoral. Clearly, lawbreakers ought to be punished. Yet, no matter how horrific their deeds, as the targeting of Israeli civilians indeed is, they should be punished according to the law. David's arguments could, in principle, justify the abolition of formal legal systems altogether".

Targeted killing has become a frequent tactic of the United States and Israel in their fight against terrorism.[42][53] The tactic can raise complex questions and lead to contentious disputes as to the legal basis for its application, who qualifies as an appropriate "hit list" target, and what circumstances must exist before the tactic may be employed.[42] Opinions range from people considering it a legal form of self-defense that reduces terrorism, to people calling it an extra-judicial killing that lacks due process, and which leads to further violence.[42][45][54][55] Methods used have included firing a five-foot-long Hellfire missile from a Predator or Reaperdrone (an unmanned, remote-controlled plane), detonating a cell phone bomb, and long-range sniper shooting. Countries such as the U.S. (in Pakistan and Yemen) and Israel (in the West Bank and Gaza) have used targeted killing to eliminate members of groups such as Al-Qaeda and Hamas.[42] In early 2010, with President Obama's approval, Anwar al-Awlaki became the first U.S. citizen to be publicly approved for targeted killing by the Central Intelligence Agency (CIA). Awlaki was killed in a drone strike in September 2011.[56][57]

One of the earliest forms of defense against assassins was employing bodyguards. Bodyguards act as a shield for the potential target, keeping lookout for potential attackers (sometimes in advance, for example on a parade route), and putting themselves in harm's way—both by simple presence, showing that physical force is available to protect the target,[36][61] and by shielding the target during any attack. To neutralize an attacker, bodyguards are typically armed as much as legal and practical concerns permit.

Notable examples of bodyguards include the Roman Praetorian Guard or the Ottoman Janissaries—though, in both cases, the protectors sometimes became assassins themselves, exploiting their power to make the head of state a virtual hostage or killing the very leaders they were supposed to protect. The fidelity of individual bodyguards is an important question as well, especially for leaders who oversee states with strong ethnic or religious divisions. Failure to realize such divided loyalties led to the assassination of Indian Prime MinisterIndira Gandhi, assassinated by two Sikh bodyguards in 1984.

This bodyguard function was often executed by the leader's most loyal warriors, and was extremely effective throughout most of early human history, leading assassins to attempt stealthy means, such as poison (which risk was answered by having another person taste the leader's food first).

Another notable measure is the use of a body double, a person who looks like the leader and who pretends to be the leader to draw attention away from the intended target.

With the advent of gunpowder, ranged assassination (via bombs or firearms) became possible. One of the first reactions was to simply increase the guard, creating what at times might seem a small army trailing every leader; another was to begin clearing large areas whenever a leader was present, to the point where entire sections of a city might be shut down.

As the 20th century dawned, the prevalence and capability of assassins grew quickly, as did measures to protect against them. For the first time, armored cars or limousines were put into service for safer transport, with modern versions virtually invulnerable to small arms fire, smaller bombs and mines.[62]Bulletproof vests also began to be used, which were of limited utility, restricting movement and leaving the head unprotected – so they tended to be worn only during high-profile public events, if at all.

Access to famous persons, too, became more and more restricted;[63] potential visitors would be forced through numerous different checks before being granted access to the official in question, and as communication became better and information technology more prevalent, it has become all but impossible for a would-be killer to get close enough to the personage at work or in private life to effect an attempt on his or her life, especially given the common use of metal and bomb detectors.

Most modern assassinations have been committed either during a public performance or during transport, both because of weaker security and security lapses, such as with U.S. President John F. Kennedy and former Pakistani Prime Minister Benazir Bhutto, or as part of coups d'état where security is either overwhelmed or completely removed, such as with Congolese Prime Minister Patrice Lumumba.

The methods used for protection by famous people have sometimes evoked negative reactions by the public, with some resenting the separation from their officials or major figures. One example might be traveling in a car protected by a bubble of clear bulletproof glass, such as the Popemobile of Pope John Paul II, built following an attempt at his life. Politicians often resent this need for separation, sometimes sending their bodyguards away from them for personal or publicity reasons; U.S. President William McKinley did this at the public reception where he was assassinated.[63]

Other potential targets go into seclusion, and are rarely heard from or seen in public, such as writer Salman Rushdie. A related form of protection is the use of body doubles, people with similar builds to those they are expected to impersonate. These persons are then made up, and in some cases altered to look like the target, with the body double then taking the place of the person in high risk situations. According to Joe R. Reeder, Under Secretary of the Army from 1993 to 1997, Fidel Castro used body doubles.[64]